Method for producing composite titanic-oxid products.



, Products, of whic LOUIS n. BARTON, or NIAGARA FALLS, NEW

YORK, ASSIGNOR TO THE TITANIUM ALLOY MANUFACTURING COMPANY, OF NEW YORK, N. Y., A. CORPORATION OF MAINE.

' METHOD FOR PRODUCING COMPOSITE TITANIC OXID PRODUCTS.

No Drawing. x Original application filed July 19, 1915, Serial No. 40,639. Divided and June 8, 1916. Serial No. 102,393.

To all whom it may concern:

Be it known that I, LOUIS E. BARTON, a citizen of the United States, and a resident of Niagara Falls, in the county. of Niagara and State of New York, have invented certain new and useful Improvements in Methods for Producin Composite Titanic-Oxid the following is a specification, this being a division of my pending application for patent, Serial Number 40,639, filed July 19, 1915.

My present invention relates especially to such products utilized as pigments in paint, including others also, containing important percentages of titanic oxid. Its objects comprise provision of methods. whereby, as is desirable for certain purposes, composite t1- tanic .oxid pigments can be, on industrial scales of manufacture, produced by aid of precipitation of orthotitanic acid on suspended particles'of any desired substance, thus including even extender pigments of the types familiar in the paint art, there being thus imparted to the resulting products, or pigments, qualities rendering them exceptionally useful for certain purposes.

In Letters Patent No. 1,155,462, dated October 5, 1915, Ihave disclosed and claimed a process for producing compound titanic oxid products, or pigments, by aid of precipitationin those instances occurring by aid of addition of salts to hydrochloric acid solutions.

In my pending application for patent Serial Number 861,184, filed September 11, 1914, I have disclosed a process, invented by me, forobtainin pure titanic oxid by aid of precipitating metatitanic acid fromv hydrochloric acid solutions and calcining the precipitate, the final product being a soft fine powder suitable for pigment .purposes. a

I am aware that by addition to a titamc solution of a base, such as ammoma, or soda,

to neutrality of the solution, orthotitanic acid is precipitatable, but this acid thus-precipitated is, when separated, dried andcalcined', usually of too coarse and gritty consistency and texture to be Well suited for pigment purposes, although if ground to a fine powder it may, when mixed with oil,

I tatin Specification of Letters Patent. Patented Sept. 18, 1917- this application filed substances, (hereinafter referred to as sus-,

pended base thotitanic acid can, itself, or with which composite results of pigments), upon Which the orin gelatinous state, fix it can coalesce, and the such precipitation and coalescence be then filtered out and calcined, V

the final products, instead of being coarse and gritty, will prove to be extremely fine, soft, smooth, powders and correspondingly superior for such purposes ,as pigments.

My invention comprises also the discov- 5 ery that suspended bases suitable for such receptionof, and coalescence with, the thus precipitated orthotitanic acid, include the so called extender pigments used in compounding paints, such, for example, as barytes (natural barium sulfate), silica, china clay, asbestin, etc. I

I have discovered that a suitable precipiagent when such extender pigments are t we employed may be any of the alkalis, as, for example, sodium hydroxid, ammonium hydroxid, potassium carbonate, or sodium sulfid.

And a particularly important feature of my invention is my further discovery that the best final products are obtainable, and with greater economy, by operating in a titanic sulfate solution, treated with a reagent which is capable both of acting as the precipitant of the orthotitanic acid, and also of supplying by reaction with the solution the required suspended base particles. My researches have demonstrated that the alkali earth bases can be successfully used as such ployed, my product is obtained by co-precipitation of titanic hydroxid (orthotitanic last referred to reagent, viz: calcium hyacid) and the sulfate base, this resulting in v the-most intimate and homogeneous mixture 55 least 25%.of the'sulfates to e acted upon. When several preci itants are thus employed the product will be of the ingredients of the final product, and in development in the highest degree of the desired pigment properties of titanic oxid upon calcination. The final products thus obtained are fine, soft, powders consisting of amorphous, titanic oxid, coalesced with a sulfate base. I

In the various applications of my invention, the .chemi'calcomposition and specific gravity of the final products will, of course, depend upon the nature of the precipitating agent employed and the composition of the titanic solution used. j

The color of my products will, of course, depend upon the purity of the materials; thus, for example, tion employed is practically free from iron,

white, and will range from this to light, or even dark, cream color, in proportion to iron present.

I provide procedures whereby my hlghest grade product may be derived from relatively impure titanic solutions, as for, example, those containing small, quantlties of copper, insoluble in dilute acids. Such impurities I remove by passing hydrogen sulfid gas into the solution and filtering out the pre eipitated sulfid.

Should the titanic, solution contain, as an; impurity, more iron than desired, I use as the precipitating agent a sulfid, or a mixture of a sulfid base with an oxid base. In either case the ironwill be precipitated with the product as iron sulfid. For example, if it is desired -to precipitate the orthotitanic acid on a silica suspended base which. has been added as such to the solution, I add as the precipitating agent. sodium sulfid, or a mixture of sodium hydroxid, or of sodium car+ bonate, with sodium sulfid. If, on the other hand, the suspended base is, as above de scrib'ed, formed by precipitation of sulfates in a titanic sulfate solution, I add to the latter, purified from copper and other im-* purities as above described, barium sulfid as the precipitant, or a mixture of calcium hydrate and sodium sulfid, or a mixture of calcium hydrate and barium sulfid, theessen- ,tial being to add enough of the sulfid to insure the precipitation of the iron in the form of non sulfid. It is my experiencethat in such cases the precipitant substance employed should,'-for the best results, contain of the sulfid the chemical e uivalent of at together it is'usual y preferable, though not invariablynecessary, that they be mixed before additlon, but in some cases it is better to add them. successively. fFor'example, if one of the precipitants is calcium hydrate,

by first adding it separately, opportunity is if the titanic sulfate soluor other elements, whose sulfids are the resulting suspended base, required, before addition of the more quickly. reactive sulfid. s

The pigment product having thus been precipitated, I conductsulfur dioxid gas into thev solution until the iron sulfid is decomposed and dissolved. Though this may result in the solution being then slightly acid with sulfurous acid, the latter does not react to dissolve titanic acid or precipitated base more than negligibly, and therefore does not substantially impair the yield of the final product.

I first obtain, or prepare, in any convenient manner, a titanic sulfate solution, which may be either a hydrochloric, a sulfuric, or other, acid solution except that, if the suspended base is' to be formed by its precipitation therein, a titanic sulfate solution is preferable, and I will therefore, assume such to be the one employed in what follows. To such solution, I either add the desired extender pigment as such, or the precipitant or precipitants, referred to, the latter being preferably dissolved, or at least suspended in water; or in some cases,"I may add both the extender and the precipitant to the titanic solution.

From the analysis of the latter, I calculate the quantity of precipitant, ormixture of precipitants, required, the rule being that, in practically all cases, such quantity be suflicient to combine with all the sulfate in the solution except sodium sulfate. Slight discrepancles between that calculatedand required may be compensated by adding the precipitant slowly and stopping when the mixed solution shows a slightly alkaline reactlon. During the precipitation I thoroughly agitate the solution, and this-particularly if an extender pigment has been incorporated andsuspended as aforesaid toform the suspended base pigment.

After the precipitation, the solution is ready for the next step in my process, though if a part of the precipitant-has been added in undissolved, z. e; already suspended, form, r

aswould be calcium hydrate, for -gx mgk I it is'better practice to allow the-charge to 11-5 "stand with occasional agitation during an interval of say one half an hour to an hour in order to insure more complete reaction between the precipitant and the sillfatcs'in solution. 1 1 Ingoperations in which I' desire that the precipitated product shall be purified from iron in he solution, I, at this stage, incor porate sulfurous acid as by conducting sulfur dioxid gas into the charge as before de- 12!) scribed, thus decomposing and dissolving the iron sulfid present.

My next step in the operationis to 'filter out the recipitate, which I thereafter wash with 0.0 6. water, dry, and calcine at a tem- 13o perature of from say 600 C. to 800 (3., thus obtaining my final composite titanic oxld product, or pigment.

In my herewith copending-application for Letters Patent Serial Number 23,520, filed April 23, 1915, I have described and claimedwhereby,

a method, and resulting product, by aid of alkali earth bases added as precipitants to a titanic sulfate solution, there are therein precipitated sulfate particles, and also particles of basic titanic sulfate (z'. e. titanic sulfate combined with hydrated titanic oxid), the resulting uncalcined composite precipitate product being distinguished as consisting essentially of such sulfate particles coalesced with said basic titanic sulfate.

The said method of my previous application differs from that of the present, among other respects, in that the titanic pre cipitate sought and attained by the latter is orthotitanic acid instead of basic titanic sulfate, and in'that, to that end, while a titanic sulfate solution may be employed in either method, and likewise alkali earth bases as precipitants, the quantity of the latter employed in my previous method is insufficient to produce a permanent precipitate of orthotitanic acid, also in that requisite acidity of the titanic solution is, in my previous method, insured by additions of sulfuric acid, and the charge is heated and otherwise treated so as to lnsure that its titanic constituents shall precipitate in the form of basic titanic sulfate, while, by my present method, the procedure is altered so as to insure precipitation of orthotitanic acid, and, consequently, the quantity of the alkali earth base is not so restricted; titanic acid solutions other than titanic sulfate may, in certain cases, be employed as above stated, additions of acid are omitted and the charge is not heated.

Each of my said methods possesses its own characteristic and distinctive advantages in procedure and results, and as regards special uses for its respective products.

The uncalcined composite precipitate product of my present'method is of distinctive and special utility for certain purposes 1n the arts, and, when dried, it consists essentially of particles of extender pigment, or of sulfate particles, or of both, havmg therewith coalesced very minute particles of orthotitanic acid.

Having now described my invention, what I claim as new and desire to secure by Letters Patent is the following, viz:

1. In the production of composite titanic oxid products from a titanic solution, the steps which consist in suspending particles of a base pigment in such solution, and in precipitating orthotitanic acid upon said particles whlle so suspended,

2. In the production of composite titanic oxid. products from a titanic solution, the steps which consist in adding to such -solu tion an extender pigment and also adding an alkali base.

3. In the production of composite titanic oxid products from a titanic solution, the steps which consist in adding to such solution an extender pigment and also an alkali base and agitating the'charge.

4. In the production of composite titanic oxid products from a titanic solution, the steps which consist in incorporating in such solution particles of a base pigment, maintaining such particles in suspension, and adding to the charge a reagent'capable of therein precipitating orthotitanic acid.

5. The method of producing pigments containing titanic oxid from a titanic solution which comprises incorporating in such solution particles of a base pigment, maintaining such particles in suspension, adding to the charge a reagent capable of therein precipitating orthotitanic acid, withdrawing the resulting orthotitanic acid precipitate together with said particles, and calcining them. a

6. The method of producing pigments containing titanic oxid from a titanic solution, which consists in adding to such solution an extender pigment, also adding thereto an alkali base, agitating the charge, withdrawing therefrom the resulting composi-' tion of orthotitanic acid precipitate and therewith coalesced extender pigment, and calcining it.

7. The method of producing pigments containing titanic oxid from impure titanic solution which comprises passing hydrogen sulfid gas into the solution, filterin out precipitated sulfids, adding to the trate an extender pigment, also adding thereto an alkali base, agitating the charge, withdrawing therefrom the resulting composition of orthotitanic acid precipitate and therewith coalesced extender pi ment. and calcining it.

8. The method 0 producing pigments containing titanic oxid from iron-containing titanic solution which comprises adding to such solution an extender pigment, also adding thereto an alkali sulfid base, agitating the charge, incorporating therein sulfurous acid, withdrawing therefrom the resulting composition of orthotitanic acid precipitate and therewith coalesced extender pigment, and calcining such composition.

9. In the production of composite titanic oxid products from a titanic solution, the steps which consist in suspending particles in such solution, and in precipitating orthotitanic acid upon said particles while so suspended. I

10. In the production of composite titanic I oxid products from a titanic solution, the

steps which consist in mechanically adding to' said solution particles of'a'basc pigment, and in precipitating a titanic compound upon said piarticleswhile in said solution.

' 11. In t e production of titanic oxid products from a titanic solution, the steps which consist in suspending particles in such solution, and precipitating a titanic compound upon said particles while so sus- 

